The transferring and molding apparatus disclosed in Japanese Examined Patent Publication No. 01-59095 is known.
This transferring and molding apparatus includes a movable die mounted on a movable platen, a stationary die mounted on a stationary platen, an injection nozzle, a transfer film, a film feeding unit mounted above the movable platen so as to move in a widthwise direction of the transfer film, a film winding unit mounted below the movable platen so as to move in a widthwise direction of the transfer film, and a position detecting unit for the transfer film.
The transfer film is moved in a lengthwise direction with the dies open, and stopped at the transfer transfer position when the position detecting unit has detected the position of the transfer film, after which a molten resin is injected from the injection nozzle with the dies closed so as to hold the transfer film therebetween, to transfer the pattern provided on the transfer film onto a molded article concurrently with the molding, and to thereby produce a molded article having the pattern transferred from the transfer film at a predetermined position.
In the aforementioned transferring and molding apparatus, the transfer film is positioned in the transfer position as follows.
More specifically, the position detecting unit is provided including a lengthwise direction sensor that detects a lengthwise direction mark of the transfer film, and first and second widthwise direction sensors that detect a widthwise direction mark of the transfer film, all of which are optical sensors. For the lengthwise positioning, the transfer film is moved lengthwise until the lengthwise direction sensor detects the lengthwise direction mark of the transfer film, at which point the film feeding unit and the film winding unit stop the movement of the transfer film.
For the widthwise positioning, the film feeding unit is moved widthwise with respect to the transfer film until the first widthwise direction sensor detects the widthwise direction mark of the transfer film, and the film winding unit is moved widthwise with respect to the transfer film until the second widthwise direction sensor detects the widthwise direction mark of the film, and once the first and the second widthwise direction sensors have detected the widthwise direction mark, the film feeding unit and the film winding unit are stopped.
That is, the transferring and molding method with the transferring and molding apparatus is a method for repeating the transferring and molding processes of positioning the transfer film in the transfer position by moving the transfer film in the die open state, thereafter placing the transfer film in the die closed state and then injecting the molten resin into the cavity for the transfer of the pattern of the transfer film in the prescribed position of the molded article concurrently with molding.
The conventional transferring and molding method has a process for positioning the transfer film in the transfer position so as to make the pattern of the transfer film position face the prescribed position of the die (molding section). Even through this process, the pattern transferred onto the molded article is sometimes shifted as a consequence of repetitively carrying out the aforementioned transferring and molding process.
For example, when wrinkles occur on the transfer film during the transferring and molding, a pattern shift occurs. The wrinkles of the transfer film are prominently created especially when the configuration of the molded article is bent in a convex shape in placing the transfer film between the dies or when a plurality of molding sections are formed on the die.
As described above, since the positioning of the transfer film is performed based on the position of the lengthwise direction mark and widthwise direction mark provided on the transfer film in the conventional transferring and molding method, the position of the transferred pattern is often shifted while repeating the transferring and molding process. Such a position shift can be corrected by correcting the transfer position for the transfer film; however, the transferring and molding process has to be suspended for the repositioning of the transfer film.
The present invention is made in view of the aforementioned problems, and the object thereof is to provide a transferring and molding method and transferring and molding apparatus capable of producing a molded article on which a pattern is transferred in a prescribed position by automatically correcting the position of a transfer film when there is produced a molded article on which the transferred pattern is shifted.